The present invention relates to a sample injector for a sample separation system, in particular for high performance liquid chromatography applications.
In liquid chromatography, a fluidic sample and an eluent (liquid mobile phase) may be pumped through conduits and a column in which separation of sample components takes place. In a sample loop, the sample may be injected into a fluidic path by a mechanically drivable needle. The drivable needle is controllable to be moved out of a seat of the sample loop into a vial or any other fluid container to receive a fluid and back from the vial into the seat. The column may comprise a material which is capable of separating different components of the fluidic analyte. Such a material, so-called beads which may comprise silica gel, may be filled into a column tube which may be connected downstream to other components, such as a detector, a fractioner, a waste, etc., by conduits.
U.S. Pat. No. 7,555,937 discloses a sample injection device, a sample injection method, and a liquid chromatograph that control the flow of a mobile phase using a switching valve. The sample injection device includes a port connected to a separation column, a pump for supplying a mobile phase, first and second sample injection needles, a syringe, and a valve configured to selectively connect the first sample injection needle to the pump or the syringe and to connect the second sample injection needle to the pump. When the first sample injection needle is attached to the port, the first sample injection needle is connected to the pump through operation of the valve. When the second sample injection needle is attached to the port, the first sample injection needle is connected to the syringe and the second sample injection needle is connected to the pump.
U.S. Pat. No. 7,635,326 discloses a tool holder which can be displaced in an x-direction, in a y-direction that is perpendicular thereto, and in a z-direction that is perpendicular to both the x-direction and the y-direction, and which can rotate about the z-direction. A solid matter dosing head, provided as a tool, is automatically attached in a removable manner to the tool holder by means of a permanent magnet. The tool can be easily exchanged for another tool due to this automatic removable attachment of said tool to the tool holder involving the use of a permanent magnet.
DE 102007000622, EP 1,366,822, and U.S. Pat. No. 7,138,050 disclose further fluid handling systems.
The product G1367 of the applicant Agilent Technologies is an example for a commercially available needle assay well plate autosampler.
However, fluid handling and proper operation of movable parts in a sample separation device may still be a challenge.